diesel402004

Still chasing this issue, and noticed that my 4WD shifter wobbles also when the low speed shudder is present (can actually put my hand on it and feel it pulsate). Do others with this shudder--sometimes associated with the rear diff--feel this? After replacing almost all the driveline components I'm looking at other possibilities.

Things done so far....
Tranny - check
tranny mounts - check
all fluids - check
forward u-joint - check
carrier bearing - check
tsb for carrier bearing - check
middle and rear u-joints - appear fine
powerlock lsd - check (new 1.5 years ago)
phasing of driveshaft slipline - check

Did any of yous notice the 4WD lever moving during the shuddering (before the fix).

when rear driveline is dropped and 4wd engaged there is no apparent shudder

D

mknittle

My old 727 did it when just starting out from a stop. turned out to be a valve went bad in the valve body. the dealer replaced the driveline and that did nothing so it went back. Next round they checked the transmission and found the valve that was galded. it worked good for 10 years after that. until I took it out.

Philip

Dodge released a TSB about this issue. What they said to do was drop the carrier bearing down from its current position. I think they said use a 1/2" thick spacer. I started with a 1/4". It dropped the vibrations some. I added another 1/4" spacer and the problem went away.

I just used a piece of 1/4" flat stock the width of the carrier bearing mount. Drill the holes for the carrier bearing mount spacing.

I went threw my TSB book. The TSB # 03-02-93

TSB 03-02-93

NJTman

I did the same thing. Used some 1/2" thick washers, and I was done. Never did anything since then, and that was some 6 years ago.

cougar

I have a similar problem, it is at low speeds, decelerating or constant. The truck will slowly bounce up and down. My 91.5 also did it and it was a short wheel base 5 speed.

Philip

Newbie owner

I did mine around 1998 or so. The first thing I did for the truck when I got it was to order all the manuals and the TSB book. I found that TSB one night setting back watching TV.

gyman98

Lifting the rear will make it worse, Rule of thumb is 1/4" per inch added to the rear. This would be in addition to the 1/2" needed for a stock truck

sdseva

can anyone post pictures of this fix?? pleeease

diesel402004

UPDATE:
No surprise, but after 2yrs of chasing this worsening driveline shudder I decided to check all the u-joints again--even though they were newer. Sure enough the middle joint was showing a slight wobble during acceleration and I decided to replace it. FIXED! No more shudder. Lesson learned: start with the obvious simple stuff even though it may not be logical.

NJTman

K.I.S.S.

Keep It Simple Stupid

Personally, I have found that a good majority of manufacturers of U joints, as well as other parts for our rides, are designed for rapid failure. I replaced U joints in my brick's front D60 axle every two years like clockwork, and yet I greased them many many times over their lifespan. With how infrequent the front axles turn in my truck (from december through march) you would think that they'd last a bit longer. After dissecting each u-Joint, I found failure wasn't preventable, as they were blocked internally, preventing grease passage to 2 caps. Each replacement set had the same ending.

Now I use Spicer Non greasables. 2 + years and counting, but so far, nothing unusual.

Advance Auto U joints after 2 years of part time use:

mknittle

I never cared for the non greasables but after much searching and reading I am going to put them in mine when i get there.

johnh

i know my truck is only 2wd, but the u joints are original @280,000 miles

mknittle

One more reason Thanks John. The seals are supposed to a lot better so I can see why they would last longer.

Philip

The 2WD has a lot less drive line angles than our $X$ does. That makes for longer life on a lot of rear suspension parts.

NJTman

And better fuel mileage as well....